JP4453142B2

JP4453142B2 - Electronic blood pressure monitor

Info

Publication number: JP4453142B2
Application number: JP2000021615A
Authority: JP
Inventors: 義明渡邉
Original assignee: Panasonic Corp; Matsushita Electric Works Ltd
Current assignee: Panasonic Corp; Panasonic Electric Works Co Ltd
Priority date: 2000-01-31
Filing date: 2000-01-31
Publication date: 2010-04-21
Anticipated expiration: 2020-01-31
Also published as: JP2001204696A

Description

【０００１】
【発明の属する技術分野】
本発明は、人体の血圧を測定する血圧計に関するものであり、特に被験者の精神状態を検出して測定された血圧値を評価する電子血圧計に関するものである。
【０００２】
【従来の技術】
従来のこの種の電子血圧計は、腕や手首にカフを巻き付けカフに最高血圧以上の圧力を加えて血流を一時的に阻害した後に、徐々にカフの圧力を下げその過程で脈音が発生する時点と消失する時点の圧力から最高血圧値と最低血圧値を決定するコロトコフ音法や、同じくカフ圧の減圧過程における心拍に同期して発生するカフの微小な圧力変動の振幅の変化を用いて血圧値を決定するオシロメトリック法を用いて人体の血圧を決定するものが多い。
【０００３】
また、血圧値は被験者の精神状態によって変化し、リラックスした時は低く、興奮している時は高くなるので、高血圧の診断をする場合、興奮した状態で血圧を測定してしまうと、通常よりも血圧が高く測定されてしまい、正しい診断ができないことが多くあった。例えば、白衣高血圧と呼ばれる現象があり、これは、医者の前にいると、医者に対する恐怖感や緊張感などから血圧が上昇してしまい、医者によって計測された血圧値が通常の生活状態における血圧値を反映してないという高血圧の診断上困難な問題が存在している。
【０００４】
このような問題を解決するために、例えば、特開平９−２２０２０５号公報では、心拍周期の揺らぎから被験者の交感神経の興奮度を検出し、この興奮度が所定値以下となった時に限り血圧測定を行うようにしている。この構成によって、測定される血圧値は被験者の緊張が十分に解消された状態にあるときのみ血圧値を測定するので、信頼性の高い血圧値が安定して測定される。
【０００５】
【発明が解決しようとする課題】
しかしながら、上記従来の電子血圧計では、被験者の緊張が十分に解消された場合にのみ血圧値の測定が開始されるため、緊張を解消させるために測定の前に安静を保つ必要があるが、緊張が解消せず長時間安静を保つ必要がある場合にはなかなか血圧測定を開始できず、却ってイライラしてしまいさらに長時間血圧測定ができない場合もあった。また、緊張状態の検出においては、個人差が大きく、ある揺らぎの大きさが検出されても被験者によってその緊張状態が異なる場合も多くあった。
【０００６】
【課題を解決するための手段】
本発明は上記課題を解決するため、人体の四肢に装着され内部の圧力変化によって装着部位の血液流動を阻害する加圧手段と、前記加圧手段に圧力を加える圧力発生手段と、前記加圧手段の圧力を調整する圧力調整手段と、前記加圧手段の圧力を検出する圧力検出手段と、前記加圧手段と加圧部位の血圧との関係により変化する生体情報を検出する生体情報検出手段と、前記生体情報検出手段の出力と圧力検出手段の出力とから前記人体の血圧値を決定する血圧値決定手段と、前記人体の精神状態を検出する精神状態検出手段を備え、前記精神状態検出手段は加圧手段により加圧される前後の精神状態の変化により、血圧測定時の前記人体の精神状態を検出するものである。
【０００７】
上記発明によれば、精神状態検出手段が、加圧手段が上肢を加圧する際の安定した刺激を用い、その前後の精神状態により変化する生体情報の変化を検出して被験者の精神状態を検出できるので、個人差のない精神状態の検出ができる。さらに、血圧を測定しながら精神状態を検出するので、精神状態が安定するまで待つ必要がない。
【０００８】
【発明の実施の形態】
本発明の請求項１にかかる電子血圧計は、人体の四肢に装着され内部の圧力変化によって装着部位の血液流動を阻害する加圧手段と、前記加圧手段に圧力を加える圧力発生手段と、前記加圧手段の圧力を調整する圧力調整手段と、前記加圧手段の圧力を検出する圧力検出手段と、前記加圧手段と加圧部位の血圧との関係により変化する生体情報を検出する生体情報検出手段と、前記生体情報検出手段の出力と圧力検出手段の出力とから前記人体の血圧値を決定する血圧値決定手段と、前記人体の精神状態を検出する精神状態検出手段を備え、前記精神状態検出手段は前記加圧手段により加圧される前後の精神状態の変化により、血圧測定時の前記人体の精神状態を検出する電子血圧計であって、前記加圧手段に配置された第一の筋電電極とケースに配置された第二の筋電電極とこれら二つの電極の電位差から筋電信号を検出す筋電信号検出手段を有し、第一の筋電電極は前記加圧手段の皮膚と接触する位置に、第二の筋電電極はケース表面にそれぞれ配置され、第二の電極は前記精神状態検出手段による精神状態が検出されている間前記加圧手段を装着している側の上肢の一部が接触し、前記精神状態検出手段は筋電信号検出手段から得られる筋電図を用いて人体の精神状態を検出する。
【００１１】
そして、精神状態検出手段が、加圧手段が上肢を加圧する際の安定した刺激を用い、その前後の精神状態により変化する生理情報の変化を検出して被験者の精神状態を検出できるので、個人差のない精神状態の検出ができる。さらに、血圧を測定しながら精神状態を検出するので、精神状態が安定するまで待つ必要がない。加えて、加圧手段が接触した側の上肢の２点に接触した一対の電極から得られた筋電図の変化から人体の精神状態を検出するので、正確かつ簡単に人体の精神状態を検出できる。
【００１２】
本発明の請求項２にかかる電子血圧計は、血圧値決定手段が決定した血圧値とその時点の精神状態検出手段が検出した精神状態とを複数回記憶する記憶手段を有し、記憶手段に記憶された複数回の血圧測定値と精神状態の関係と新たに測定された血圧値と精神状態とから人体の精神状態の影響を排除した精神状態補正血圧値を推定する精神状態補正血圧推定手段を持つ。
【００１３】
そして、複数の血圧値とその時点での精神状態で被験者の血圧値と精神状態との関係を知ることができるので、新たに測定された血圧値と精神状態との関係と記憶手段に記憶された被験者の血圧値と精神状態との関係とをひかくすることによって、精神状態の影響を取り除いた血圧の評価が可能になる。
【００１８】
【実施例】
以下、本発明の基本構成、並びに実施例について図面を用いて説明する。
【００１９】
（基本構成）
図１は本発明の基本構成における電子血圧計のブロック図、図２は同装置の外観図である。なお、本基本構成の血圧計は人体の手首部をカフを用いて加圧する手首式電子血圧計の例を示し、図２では、（ａ）は通常の血圧測定時の状態、（ｂ）は精神状態補正血圧を表示させた状態を示す。図１において、１は人体の上腕を加圧する圧力印加手段であるカフ、２はカフ１に圧力を供給する加圧手段である加圧ポンプ、３はカフ２の空気を少しづつ排気して圧力を徐々に減圧する圧力調整手段である微速排気弁、４は測定終了時や異常時に急速に開放しカフ圧を大気圧に戻す急速排気弁、５はカフ１内の圧力検出手段である圧力センサ、６は圧力センサ５の出力信号からＤＣ成分をカットし心臓の活動に同期した微小な圧力変化を示す脈波を抽出して出力する生体信号検出手段である脈波検出手段、７は圧力センサ５の出力と脈波検出手段６の出力とから人体の血圧値を決定する血圧値決定手段であり、また、これらの制御を司る制御手段８と測定の開始を指示するスタートボタン９、測定結果を表示するＬＣＤからなる表示手段１０である。これらのうちカフ１、加圧ポンプ２、微速排気弁３および急速排気弁４はゴム管１１により空気圧がもれないように接続されている。また、血圧値決定手段７は、脈波検出手段６の出力の心拍の一拍毎の脈波の振り幅を用いカフ１の圧力に対する脈波の振り幅の変化の様子が被験者の血圧値に強く関係することを用いて血圧を決定するオシロメトリック法を用いて血圧値を決定している。さらに、カフ１の人体の手首に接触する位置に第一の心電電極１３が配置され、また、カフ１の接続された本体ケース１２上に第二の心電電極１４が配置されて、第二の心電電極１４にカフ１が装着されていない側の上肢の一部を接触させることにより、心電検出手段１５により第一の心電電極１３と第二の心電電極１４の電位差を検出し、これによって左右の上肢による心電波形を誘導することができる。この波形は心拍間隔算出手段１６に出力され、さらに精神状態検出手段１７に出力されて、人体の精神状態が検出される。なお、この精神状態検出手段１７の出力と血圧値決定手段７の出力とを記憶する記憶手段１８を持ち、複数回の血圧値決定手段７の決定した血圧値の測定結果と精神状態検出手段１７が検出した被験者の精神状態を記憶させることが可能になっている。
【００２０】
次に動作、作用について説明する。血圧を測定する人体がカフ１を上腕の周囲に巻きつけスタートボタン１０を押すと、まず、血圧測定前の基準状態の測定が開始される。人体がカフ１を装着してない側の手指を本体ケース１２表面に配置された第二の心電電極１４に接触させると、カフ１が手首に装着された時点で手首の皮膚表面に接触した第一の心電電極１３と第二の心電電極１４との間の電位差から心電波形検出手段１５にて左右の上肢による心電波形が誘導されて、この信号から心拍間隔算出手段１６が心電波形のＲ−Ｒ間隔を用いて心拍間隔を算出し、これが精神状態検出手段１７に出力される。精神状態検出手段１７では、心拍間隔のデータからその呼吸に起因する０．３Hz付近の揺らぎと血圧に起因する０．１Hz付近の揺らぎの大きさを算出し、制御手段９はこの値を受け取り記憶手段１８に記憶しておく。基準状態の測定が終了すると、次に血圧測定が開始され、制御手段９が加圧ポンプ２を動作させ、発生した圧力がゴム管１１を通じてカフ１に供給されてカフ１が巻き付けられた人体の手首部を加圧する。
【００２１】
この時、制御手段９は圧力センサ５の出力をモニターし、カフ１の圧力が人体の最高血圧値より高くなるようにあらかじめ決められた加圧目標値を越えた場合に加圧ポンプ２の動作を停止して加圧を止め、微速排気弁３によりカフ１の空気を少しづつ排気して圧力を徐々に減圧していく減圧動作に移行する。この時、圧力センサ５の出力には心臓の活動による血管の振動がカフ１に伝達されるため微小な圧力変化が現れ、脈波検出手段６が圧力センサ５の信号からＤＣ成分を除去し脈動成分のみを取り出して脈波を抽出し、血圧値決定手段７では脈波検出手段６の出力信号から心臓の１拍毎の波形に分割された各波形の振幅を算出し、この値と圧力検出手段５の出力とからオシロメトリック法により被験者の血圧値を決定している。一方、血圧測定中も、心電検出手段１５の心電検出と心拍間隔算出手段１６の心拍間隔の算出が行われて精神状態検出手段１７に出力され、精神状態検出手段１７では、カフによる加圧刺激時の心拍間隔の変化を検出し、この時の揺らぎとカフ加圧前の心拍間隔の揺らぎとを比較して、被験者の精神状態を検出している。
【００２２】
図３にカフ加圧前後の心拍間隔の変化の様子を示す。図中Ａはカフ加圧前の基準状態、Ｂは圧力発生手段によりカフに圧力が加えられてカフ圧が上昇している状態、Ｃは圧力発生手段によるカフ圧の上昇が停止し減圧中の状態、Ｄは血圧測定が終了しカフ圧が大気圧に開放された状態である。加圧カフによる加圧が開始されると、図中Ｂで示されるように心拍間隔は一旦短縮し、加圧が停止し微速排気状態に移行すると再び回復し、カフ加圧前の状態と同程度または多少延長された状態となり、測定が終了すると共にカフ加圧前の心拍間隔に落ち着く。また、呼吸による０．３Hz付近の揺らぎや血圧による０．１Hz揺らぎもカフ加圧前後で変化する（図示せず）が、このような心拍間隔やゆらぎの変化は被験者がリラックスしている時には大きく、緊張時には少なくなる。従って、カフ加圧前後の心拍間隔や揺らぎの変化の状態を調べることによって、血圧を測定している被験者の現在のストレスの状態を検出することが可能となっている。
【００２３】
本基本構成では、カフ加圧時の心拍間隔の平均値Ｔｏを、カフ加圧前の心拍間隔の変化の大きさｔ１で除算して精神状態を数値化し、図２（ａ）に示すように表示手段１２の最下段に−５から＋５の１１段階で表示している。この１１段階の表示は多人数による精神状態の測定データから確率分布を求め、この分布から統計的に換算式を算出して１１段階の表示に換算している。
【００２４】
さらに、本基本構成では、過去数回の血圧値と精神状態検出結果とを記憶手段１８に記憶させておき、演算手段１９により両者の関係式を求めている。演算手段１９の演算結果を用いて精神状態補正血圧推定手段２０が、新たに測定した血圧値と精神状態との関係について、演算手段１９が算出した関係式からどれだけ離れているかを調べ、その値を表示手段１０に表示し、さらに、関係式からの差があらかじめ決められた値より大きい場合に、血圧値と精神状態との関係が変化したとみなし、被験者に報知している。血圧値と精神状態の関係の一例を図４に示す。図中横軸は精神状態検出手段の出力でカフ加圧前後の心拍間隔の変化率（ｔ１／Ｔｏ）、縦軸は収縮期血圧であり、図のようにばらつきはあるが、両者は負の相関を示す。この回帰直線から縦軸に平行な方向の距離は、平均的な関係からどれだけ離れているかを示し、同じリラックス状態に換算した時に血圧値が変化したかを判断する指標となる。この距離を用いることにより、精神状態によらず血圧がどのように変化したかが分かるので、精神状態に左右されずに血圧値の動向の正しい把握が可能になる。例えば、新たに測定された血圧値と精神状態のデータが図中Ａにプロットされた場合、血圧値は自体は平均に近いが、精神状態検出手段がリラックスしていると判断したので、回帰直線より１０mmHg上方にあり、血圧の状態が上昇側に行っていることを示している。このような判定は、表示切り替えスイッチ２１を押すことにより、図２（ｂ）に示すように過去の精神状態と血圧値との回帰直線のグラフと新たに採取したデータとを表示手段１０に表示させている。
【００２５】
（実施例）
図５に本実施例の電子血圧計のブロック図、図６に本実施例の電子血圧計の外観図を示す。本実施例の電子血圧計はカフを上腕に巻き付け、カフと本体が分離している上腕分離式の血圧計となっている。
【００２６】
本実施例が基本構成と異なる点は、精神状態検出手段１７が用いる生理情報が筋電図であり、カフを装着した側の腕の筋電図を検出して精神状態を検出する点にある。
【００２７】
被験者の精神状態を検出するに当たっては、心拍間隔の変動とともに筋電図も有効である。図７にカフ加圧前後の筋電図の振り幅の変化の様子を示す。図のようにカフ加圧前（図中Ａ）ではほぼ一定値Ｖｏとなるのに対しカフ加圧時（Ｂ）にカフ加圧の刺激によって筋の収縮が見られ、瞬間的に筋電図の振り幅は上昇する。カフの圧力上昇が停止し微速排気状態に移行（Ｃ）しても継続して筋電図の振り幅は大きなまま（Ｖ１）で、血圧測定が終了してカフの圧力が開放される（Ｄ）と、筋電図の振り幅は回復する。このカフ加圧中の筋電図の振り幅上昇はカフ加圧前の緊張状態によって変化し、リラックス状態では振り幅の増加は大きく、緊張状態では小さくなる。本実施例ではこのように変化するカフ加圧前後の筋電図の振り幅の変化Ｖ１／Ｖｏを算出し、血圧測定を行っている人体の精神状態を検出し、基本構成の電子血圧計と同様な処理が可能となっている。
【００２８】
なお、本実施例の電子血圧計では筋電図を採取する電極を一方（第一の筋電電極２２）をカフの腕と接触する表面に、もう一方（第二の筋電電極２３）をカフと分離して配置される本体ケース１２表面に配置され、筋電検出手段２４により第一の筋電極２２と第二の筋電電極２３との間の電位差から筋電図を検出している。血圧測定時は、被験者は本体ケース１２表面の第二の筋電電極２３の上に手首を乗せて、血圧と筋電図の測定を同時に行う構成としている。これによって、心電信号と同様に簡単に血圧測定と筋電図による精神状態検出を同時に行うことができる。図８に左腕を用いた計測時の外観図を示す。
【００２９】
なお、以上の実施例では、血圧測定時は一度加圧した後に微速排気させ、微速排気時にカフ１に発生するカフ圧の微少な変化から脈波を採取しているが、微速に排気せずに、徐々に加圧しその過程での脈波の変化を用いるものでもよい。また、カフ圧の微小な変化による脈波を用いずにカフ圧の変化により発生するコロトコフ音を用いて血圧を決定する構成でもよい。
【００３０】
また、以上の実施例では、微速排気弁は制御手段の制御を受けているが、制御を受けず、機構的にカフの減圧速度を一定に保つものでもよい。
【００３１】
上記に示すように本発明の電子血圧計は、血圧採取の際に被験者の精神状態も検出し、検出された精神状態に基づいて測定された血圧値を評価できるので、精神状態に左右されず適切な循環系の診断を行うことができる電子血圧計を提供できる。
【００３２】
【発明の効果】
以上説明したように本発明の請求項１に係る電子血圧計は、精神状態検出手段が、加圧手段が上肢を加圧する際の安定した刺激を用い、その前後の精神状態により変化する生体情報の変化を検出して被験者の精神状態を検出できるので、個人差のない精神状態の検出ができる。さらに、血圧を測定しながら精神状態を検出するので、精神状態が安定するまで待つ必要がない。加えて、加圧手段が接触した側の上肢の２点に接触した一対の電極から得られた筋電図の変化から人体の精神状態を検出するので、正確かつ簡単に人体の精神状態を検出できる。
【００３４】
また、請求項２に係る電子血圧計は、複数の血圧値とその時点での精神状態で被験者の血圧値と精神状態との関係を知ることができるので、新たに測定された血圧値と精神状態との関係と記憶手段に記憶された被験者の血圧値と精神状態との関係とをひかくすることによって、精神状態の影響を取り除いた血圧の評価が可能になる。
【図面の簡単な説明】
【図１】本発明の基本構成における電子血圧計のブロック図
【図２】（ａ）同装置の実測血圧表示中の外観図
（ｂ）同装置の精神状態補正血圧表示中の外観図
【図３】同装置の心拍間隔算出手段の出力波形図
【図４】同装置のカフ加圧前後の心拍間隔変化率と収縮期血圧との関係図
【図５】本発明の実施例における電子血圧計のブロック図
【図６】同装置の外観図
【図７】同装置の筋電信号出力手段の出力波形図
【図８】同装置の計測時の外観図
【符号の説明】
１カフ（圧力印加手段）
２加圧ポンプ（加圧手段）
３微速排気弁（圧力調整手段）
５圧力センサ（圧力検出手段）
６脈波検出手段
７血圧値決定手段
１２ケース
１３第一の心電電極
１４第二の心電電極
１７精神状態検出手段
１８記憶手段
２０精神状態補正血圧推定手段
２１表示切り替えスイッチ
２２第一の筋電電極
２３第二の筋電電極
２４筋電検出手段[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a sphygmomanometer that measures the blood pressure of a human body, and more particularly to an electronic sphygmomanometer that detects a mental state of a subject and evaluates the measured blood pressure value.
[0002]
[Prior art]
This type of conventional electronic blood pressure monitor wraps the cuff around the wrist or wrist, applies pressure above the maximum blood pressure to the cuff and temporarily impedes blood flow, then gradually lowers the cuff pressure and makes a pulse sound in the process The Korotkoff sound method, which determines the systolic blood pressure and the systolic blood pressure from the pressure at the time of occurrence and the time of disappearance, and the change in the amplitude of the minute pressure fluctuation of the cuff that occurs in synchronization with the heartbeat in the decompression process of the cuff pressure. In many cases, the blood pressure of a human body is determined using an oscillometric method that determines a blood pressure value.
[0003]
In addition, blood pressure values vary depending on the mental state of the subject and are low when relaxed and high when excited, so when diagnosing hypertension, if you measure blood pressure in an excited state, In many cases, however, blood pressure was measured high, making correct diagnosis impossible. For example, there is a phenomenon called white coat hypertension. This is because when you are in front of a doctor, blood pressure rises due to fear or tension in the doctor, and the blood pressure measured by the doctor is the blood pressure in normal living conditions. There is a difficult problem in the diagnosis of hypertension that does not reflect the value.
[0004]
In order to solve such a problem, for example, in Japanese Patent Application Laid-Open No. 9-220205, the degree of excitement of the subject's sympathetic nerve is detected from fluctuations in the heartbeat period, and the blood pressure is limited only when the degree of excitement falls below a predetermined value. Measurement is performed. With this configuration, since the measured blood pressure value is measured only when the subject's tension is sufficiently eliminated, a highly reliable blood pressure value is stably measured.
[0005]
[Problems to be solved by the invention]
However, in the conventional electronic sphygmomanometer, since the measurement of the blood pressure value is started only when the subject's tension is sufficiently resolved, it is necessary to keep rest before the measurement in order to eliminate the tension, When tension did not go away and it was necessary to remain at rest for a long time, blood pressure measurement could not be started easily. Moreover, in the detection of the tension state, there are many individual differences, and even when a certain fluctuation magnitude is detected, the tension state often differs depending on the subject.
[0006]
[Means for Solving the Problems]
In order to solve the above-described problems, the present invention provides a pressurizing unit that is mounted on the extremity of a human body and inhibits blood flow in the mounting site due to a change in internal pressure, a pressure generating unit that applies pressure to the pressurizing unit, and the pressurizing unit Pressure adjusting means for adjusting the pressure of the means, pressure detecting means for detecting the pressure of the pressurizing means, and biological information detecting means for detecting biological information that changes depending on the relationship between the pressurizing means and the blood pressure of the pressurizing part. The blood pressure value determining means for determining the blood pressure value of the human body from the output of the biological information detecting means and the output of the pressure detecting means, and the mental state detecting means for detecting the mental state of the human body, The means detects the mental state of the human body at the time of blood pressure measurement based on a change in mental state before and after being pressurized by the pressurizing means.
[0007]
According to the above invention, the mental state detecting means detects the mental state of the subject by detecting a change in biological information that changes depending on the mental state before and after the stable stimulation when the pressurizing means pressurizes the upper limb. It is possible to detect mental states without individual differences. Furthermore, since the mental state is detected while measuring the blood pressure, there is no need to wait until the mental state is stabilized.
[0008]
DETAILED DESCRIPTION OF THE INVENTION
An electronic sphygmomanometer according to claim 1 of the present invention is a pressurizing unit that is worn on the extremities of a human body and that inhibits blood flow in the wearing site due to a change in internal pressure, a pressure generating unit that applies pressure to the pressurizing unit, A pressure adjusting means for adjusting the pressure of the pressurizing means; a pressure detecting means for detecting the pressure of the pressurizing means; and a living body for detecting biological information that changes depending on the relationship between the pressurizing means and the blood pressure of the pressurizing part. An information detecting means; a blood pressure value determining means for determining a blood pressure value of the human body from an output of the biological information detecting means and an output of the pressure detecting means; and a mental condition detecting means for detecting a mental condition of the human body, The mental state detecting means is an electronic sphygmomanometer that detects the mental state of the human body at the time of blood pressure measurement based on a change in the mental state before and after being pressurized by the pressurizing means. A myoelectric electrode And a myoelectric signal detecting means for detecting a myoelectric signal from a potential difference between these two electrodes, and the first myoelectric electrode is in contact with the skin of the pressurizing means. In the position, the second myoelectric electrodes are respectively arranged on the surface of the case, and the second electrode is one of the upper limbs on the side where the pressurizing means is worn while the mental state is detected by the mental state detecting means. The mental state detection means detects the mental state of the human body using the electromyogram obtained from the myoelectric signal detection means .
[0011]
And since the mental state detection means can detect the subject's mental state by using a stable stimulus when the pressurizing means pressurizes the upper limb and detecting a change in physiological information that changes depending on the mental state before and after that, Can detect mental states without any difference. Furthermore, since the mental state is detected while measuring the blood pressure, there is no need to wait until the mental state is stabilized . In addition, since the mental state of the human body is detected from changes in the electromyogram obtained from a pair of electrodes in contact with the two points on the upper limb on which the pressurizing means is in contact, the mental state of the human body is accurately and easily detected. I can .
[0012]
The electronic sphygmomanometer according to claim 2 of the present invention has storage means for storing the blood pressure value determined by the blood pressure value determination means and the mental state detected by the mental state detection means at a plurality of times. Mental state corrected blood pressure estimating means for estimating a mental state corrected blood pressure value that excludes the influence of the mental state of the human body from the relationship between the stored blood pressure measurement values and the mental state and the newly measured blood pressure value and mental state. have.
[0013]
Since the relationship between the blood pressure value and the mental state of the subject can be known from the plurality of blood pressure values and the mental state at that time, the relationship between the newly measured blood pressure value and the mental state is stored in the storage means. By evaluating the relationship between the blood pressure value of the subject and the mental state, the blood pressure can be evaluated without the influence of the mental state.
[0018]
【Example】
Hereinafter, the basic configuration of the present invention and examples will be described with reference to the drawings.
[0019]
( Basic configuration )
FIG. 1 is a block diagram of an electronic blood pressure monitor according to the basic configuration of the present invention, and FIG. 2 is an external view of the apparatus. The sphygmomanometer of this basic configuration shows an example of a wrist electronic sphygmomanometer that pressurizes the wrist of a human body using a cuff. In FIG. 2, (a) is a state during normal blood pressure measurement, and (b) is The state which displayed the mental state correction | amendment blood pressure is shown. In FIG. 1, 1 is a cuff which is a pressure applying means for pressurizing the upper arm of a human body, 2 is a pressurizing pump which is a pressurizing means for supplying pressure to the cuff 1, and 3 is a pressure by exhausting the air in the cuff 2 little by little. 4 is a pressure exhaustion valve that is a pressure adjusting means for gradually reducing the pressure, and 4 is a quick exhaust valve that quickly opens at the end of measurement or when an abnormality occurs to return the cuff pressure to atmospheric pressure, and 5 is a pressure sensor that is a pressure detecting means in the cuff 1. , 6 is a pulse wave detecting means which is a biological signal detecting means for cutting out a DC component from the output signal of the pressure sensor 5 and extracting and outputting a pulse wave showing a minute pressure change synchronized with the activity of the heart, and 7 is a pressure sensor. 5 is a blood pressure value determining means for determining the blood pressure value of the human body from the output of the pulse wave detecting means 6, the control means 8 for controlling these, the start button 9 for instructing the start of measurement, and the measurement result Display means 1 comprising an LCD for displaying It is. Among these, the cuff 1, the pressurizing pump 2, the slow exhaust valve 3, and the quick exhaust valve 4 are connected by a rubber tube 11 so as not to have air pressure. The blood pressure value determining means 7 uses the amplitude of the pulse wave for each beat of the heartbeat output from the pulse wave detecting means 6, and the change in the amplitude of the pulse wave with respect to the pressure of the cuff 1 becomes the blood pressure value of the subject. The blood pressure value is determined by using an oscillometric method that determines the blood pressure by using a strong relationship. Furthermore, the first electrocardiographic electrode 13 is disposed at a position where the cuff 1 contacts the wrist of the human body, and the second electrocardiographic electrode 14 is disposed on the main body case 12 to which the cuff 1 is connected. By contacting a part of the upper limb on which the cuff 1 is not attached to the second electrocardiographic electrode 14, the potential difference between the first electrocardiographic electrode 13 and the second electrocardiographic electrode 14 is detected by the electrocardiographic detection means 15. By detecting it, the electrocardiogram waveform by the left and right upper limbs can be induced. This waveform is output to the heartbeat interval calculating means 16 and further output to the mental state detecting means 17 to detect the mental state of the human body. It should be noted that a storage unit 18 for storing the output of the mental state detection unit 17 and the output of the blood pressure value determination unit 7 is provided, and the measurement result of the blood pressure value determined by the blood pressure value determination unit 7 a plurality of times and the mental state detection unit 17. It is possible to memorize the mental state of the subject detected by.
[0020]
Next, the operation and action will be described. When a human body for measuring blood pressure wraps the cuff 1 around the upper arm and presses the start button 10, first, measurement of a reference state before blood pressure measurement is started. When the finger on the side where the human body does not wear the cuff 1 is brought into contact with the second electrocardiographic electrode 14 disposed on the surface of the main body case 12, the finger touches the skin surface of the wrist when the cuff 1 is worn on the wrist. From the potential difference between the first electrocardiogram electrode 13 and the second electrocardiogram electrode 14, an electrocardiogram waveform by the left and right upper limbs is induced by the electrocardiogram waveform detection means 15, and the heartbeat interval calculation means 16 is derived from this signal. The heartbeat interval is calculated using the RR interval of the electrocardiogram waveform, and this is output to the mental state detection means 17. The mental state detection means 17 calculates the magnitude of fluctuation near 0.3 Hz caused by the breath and the magnitude of fluctuation near 0.1 Hz caused by the blood pressure from the heartbeat interval data, and the control means 9 receives and stores these values. Store in the means 18. When the measurement of the reference state is completed, the blood pressure measurement is started next, the control means 9 operates the pressurizing pump 2, the generated pressure is supplied to the cuff 1 through the rubber tube 11, and the cuff 1 is wound around the human body. Pressurize the wrist.
[0021]
At this time, the control means 9 monitors the output of the pressure sensor 5, and when the pressure of the cuff 1 exceeds a predetermined pressure target value so as to be higher than the maximum blood pressure value of the human body, the operation of the pressure pump 2 is performed. Is stopped, the pressurization is stopped, and the pressure is gradually reduced by exhausting the air in the cuff 1 little by little by the slow exhaust valve 3. At this time, since the vibration of the blood vessel due to the activity of the heart is transmitted to the cuff 1 at the output of the pressure sensor 5, a minute pressure change appears, and the pulse wave detecting means 6 removes the DC component from the signal of the pressure sensor 5 and pulsates. The pulse wave is extracted by extracting only the components, and the blood pressure value determining means 7 calculates the amplitude of each waveform divided into waveforms for each beat of the heart from the output signal of the pulse wave detecting means 6, and this value and pressure detection The blood pressure value of the subject is determined by the oscillometric method from the output of the means 5. On the other hand, even during blood pressure measurement, the electrocardiogram detection of the electrocardiogram detection means 15 and the calculation of the heartbeat interval of the heartbeat interval calculation means 16 are performed and output to the mental condition detection means 17. A change in the heartbeat interval during pressure stimulation is detected, and the mental state of the subject is detected by comparing the fluctuation at this time with the fluctuation in the heartbeat interval before cuff pressurization.
[0022]
FIG. 3 shows changes in the heartbeat interval before and after cuff pressurization. In the figure, A is a reference state before cuff pressurization, B is a state where pressure is applied to the cuff by the pressure generating means, and the cuff pressure is rising, and C is a state where the cuff pressure by the pressure generating means is stopped and the pressure is being reduced. State D is a state in which blood pressure measurement is completed and the cuff pressure is released to atmospheric pressure. When pressurization by the pressurization cuff is started, the heartbeat interval is temporarily shortened as shown by B in the figure, and when the pressurization is stopped and the state is changed to the slow exhaust state, it is recovered again, and is the same as the state before the cuff pressurization. When the measurement is completed, the heartbeat interval before cuff pressurization is settled. Also, fluctuations around 0.3 Hz due to breathing and fluctuations around 0.1 Hz due to blood pressure change before and after cuff pressurization (not shown), but such changes in heart rate interval and fluctuations are large when the subject is relaxed. , Less when nervous. Therefore, it is possible to detect the current stress state of the subject whose blood pressure is being measured by examining the state of heartbeat interval and fluctuation change before and after cuff pressurization.
[0023]
In this basic configuration , the mental state is digitized by dividing the average value To of the heartbeat interval at the time of cuff pressurization by the magnitude t1 of the change in the heartbeat interval before the cuff pressurization, as shown in FIG. Displayed at 11 levels from −5 to +5 at the bottom of the display means 12. In this 11-level display, a probability distribution is obtained from the measurement data of mental states by a large number of people, and a conversion formula is statistically calculated from this distribution and converted into an 11-level display.
[0024]
Further, in this basic configuration , the blood pressure values and mental state detection results of the past several times are stored in the storage means 18 and the relational expression between them is obtained by the calculation means 19. The mental state corrected blood pressure estimation unit 20 uses the calculation result of the calculation unit 19 to examine how far the relation between the newly measured blood pressure value and the mental state is from the relational expression calculated by the calculation unit 19. A value is displayed on the display means 10, and when the difference from the relational expression is larger than a predetermined value, it is considered that the relationship between the blood pressure value and the mental state has changed, and the subject is notified. An example of the relationship between the blood pressure value and the mental state is shown in FIG. In the figure, the horizontal axis is the output of the mental state detection means, the rate of change of heart rate interval before and after cuff pressurization (t1 / To), the vertical axis is systolic blood pressure, and there are variations as shown in the figure, but both are negative Show correlation. The distance in the direction parallel to the vertical axis from the regression line indicates how far away from the average relationship, and serves as an index for determining whether the blood pressure value has changed when converted to the same relaxed state. By using this distance, it is possible to know how the blood pressure has changed regardless of the mental state. Therefore, it is possible to correctly grasp the trend of the blood pressure value regardless of the mental state. For example, when the newly measured blood pressure value and mental state data are plotted in A in the figure, the blood pressure value itself is close to the average, but it is determined that the mental state detecting means is relaxed. 10 mmHg above, indicating that the blood pressure is on the rising side. Such a determination is made by pressing the display changeover switch 21 to display a regression line graph of the past mental state and blood pressure value and newly collected data on the display means 10 as shown in FIG. I am letting.
[0025]
( Example )
FIG. 5 is a block diagram of the electronic sphygmomanometer of the present embodiment, and FIG. 6 is an external view of the electronic sphygmomanometer of the present embodiment. The electronic sphygmomanometer of this embodiment is a sphygmomanometer of the upper arm separation type in which the cuff is wound around the upper arm and the cuff and the main body are separated.
[0026]
The difference between this embodiment and the basic configuration is that the physiological information used by the mental state detection means 17 is an electromyogram, and the mental state is detected by detecting the electromyogram of the arm wearing the cuff. .
[0027]
In detecting the mental state of the subject, an electromyogram is effective together with the fluctuation of the heart rate interval. FIG. 7 shows changes in the amplitude of the electromyogram before and after cuff pressurization. As shown in the figure, before cuff pressurization (A in the figure), the value is almost constant Vo, but when cuff pressurization (B), muscle contraction is observed by cuff pressurization, and the electromyogram is instantaneously generated. The swing width of will increase. Even after the cuff pressure rise stops and transitions to the slow exhaust state (C), the amplitude of the electromyogram continues to be large (V1), the blood pressure measurement is completed, and the cuff pressure is released (D ) And the amplitude of the EMG recovers. The increase in the amplitude of the electromyogram during cuff pressurization changes depending on the tension state before the cuff pressurization, and the increase in the swing width is large in the relaxed state and is small in the tensioned state. In the present embodiment calculates the change V1 / Vo swing amount of EMG after cuff pressurization to change as this, detects the mental state of the human body are performed blood pressure measurement, and the electronic sphygmomanometer of the basic configuration Similar processing is possible.
[0028]
In the electronic sphygmomanometer of the present embodiment, one electrode (first electromyographic electrode 22) for collecting an electromyogram is placed on the surface in contact with the cuff arm, and the other electrode (second electromyographic electrode 23) is placed on the surface. The electromyogram is detected from the potential difference between the first myoelectric electrode 22 and the second myoelectric electrode 23 by the myoelectric detection means 24, which is arranged on the surface of the main body case 12 arranged separately from the cuff. . At the time of blood pressure measurement, the subject puts his / her wrist on the second electromyographic electrode 23 on the surface of the main body case 12 and simultaneously measures blood pressure and electromyogram. As a result, blood pressure measurement and mental state detection by an electromyogram can be performed simultaneously as easily as an electrocardiogram signal. FIG. 8 shows an external view at the time of measurement using the left arm.
[0029]
In the above-described embodiment, when blood pressure is measured, the pressure wave is once pressurized and then exhausted at a low speed, and the pulse wave is collected from a slight change in the cuff pressure generated in the cuff 1 at the time of the low speed exhaust, but it is not exhausted at a low speed. Alternatively, the pressure may be gradually increased and the change of the pulse wave in the process may be used. Moreover, the structure which determines the blood pressure using the Korotkoff sound generated by the change of the cuff pressure without using the pulse wave due to the minute change of the cuff pressure may be used.
[0030]
In the above embodiment, the slow exhaust valve is controlled by the control means. However, the slow exhaust valve may be mechanically maintained at a constant cuff pressure reduction speed without being controlled.
[0031]
As described above, the electronic sphygmomanometer according to the present invention can detect the mental state of the subject at the time of blood pressure collection, and can evaluate the blood pressure value measured based on the detected mental state. An electronic sphygmomanometer that can perform appropriate circulatory system diagnosis can be provided.
[0032]
【The invention's effect】
As described above, in the electronic sphygmomanometer according to claim 1 of the present invention, the mental state detecting means uses the stable stimulus when the pressurizing means pressurizes the upper limb, and the biological information changes depending on the mental state before and after that. Since the subject's mental state can be detected by detecting the change in the mental state, the mental state can be detected without individual differences. Furthermore, since the mental state is detected while measuring the blood pressure, there is no need to wait until the mental state is stabilized. In addition, since the mental state of the human body is detected from changes in the electromyogram obtained from a pair of electrodes in contact with the two points on the upper limb on which the pressurizing means is in contact, the mental state of the human body is accurately and easily detected. I can .
[0034]
In addition, since the electronic sphygmomanometer according to claim 2 can know the relationship between the blood pressure value of the subject and the mental state based on the plurality of blood pressure values and the mental state at that time, the newly measured blood pressure value and mental state By evaluating the relationship between the state and the relationship between the blood pressure value of the subject stored in the storage means and the mental state, the blood pressure can be evaluated without the influence of the mental state.
[Brief description of the drawings]
FIG. 1 is a block diagram of an electronic sphygmomanometer according to the basic configuration of the present invention. FIG. 2A is an external view of the apparatus during actual blood pressure display. FIG. 1B is an external view of the apparatus during mental state corrected blood pressure display. 3] Output waveform diagram of heart rate interval calculating means of the same device [Fig. 4] Relationship diagram of heart rate interval change rate before and after cuff pressurization and systolic blood pressure of the same device [Fig. 5] Electronic sphygmomanometer in the embodiment of the present invention [Figure 6] External view of the apparatus [Figure 7] Output waveform diagram of the electromyogram signal output means of the apparatus [Figure 8] External view at the time of measurement of the apparatus [Explanation of symbols]
1 cuff (pressure application means)
2 Pressurizing pump (pressurizing means)
3 Slow exhaust valve (pressure adjusting means)
5 Pressure sensor (pressure detection means)
6 Pulse wave detection means 7 Blood pressure value determination means 12 Case 13 First electrocardiogram electrode 14 Second electrocardiogram electrode 17 Mental state detection means 18 Storage means 20 Mental state correction blood pressure estimation means 21 Display changeover switch 22 First muscle Electrode 23 Second myoelectric electrode 24 Myoelectric detection means

Claims

A pressurizing means that is attached to the extremities of the human body and inhibits blood flow at the wearing site due to a change in internal pressure; a pressure generating means that applies pressure to the pressurizing means; and a pressure adjusting means that adjusts the pressure of the pressurizing means; A pressure detecting means for detecting the pressure of the pressurizing means, a biometric information detecting means for detecting biometric information that changes according to the relationship between the pressurizing means and the blood pressure of the pressurizing part, and an output of the biometric information detecting means. Blood pressure value determining means for determining the blood pressure value of the human body from the output of the pressure detecting means, and mental state detecting means for detecting the mental state of the human body, wherein the mental state detecting means is pressurized by the pressurizing means. An electronic sphygmomanometer that detects a mental state of the human body at the time of blood pressure measurement according to a change in a mental state before and after the blood pressure, and a second myoelectric electrode disposed in the pressurizing means and a second disposed in the case Of myoelectric electrodes and these It has a myoelectric signal detecting means for detecting a myoelectric signal from a potential difference between two electrodes, the first myoelectric electrode is in a position in contact with the skin of the pressurizing means, and the second myoelectric electrode is on the case surface. The second electrode is in contact with a part of the upper limb on which the pressurizing means is worn while the mental state is detected by the mental state detecting means, and the mental state detecting means is a myoelectric signal An electronic sphygmomanometer that detects a mental state of a human body using an electromyogram obtained from detection means .

A storage means for storing the blood pressure value determined by the blood pressure value determination means and the mental state detected by the mental state detection means at a plurality of times; a plurality of blood pressure measurement values stored in the storage means; The electronic sphygmomanometer according to claim 1, further comprising mental state corrected blood pressure estimating means for estimating a mental state corrected blood pressure value excluding the influence of the mental state of the human body from the relationship, the newly measured blood pressure value and the mental state .